Mortar-forming material



I06. COMPOSITIONS,

COATING OR PLASTIC.

UNITED STATES PATENT OFFICE.

FRITZ HARTINER, OF HOMBURG-VOB-DER-HOHE, GERMANY.

MORTAR-FORMING- MATERIAL.

No Drawing.

To all whom it may concern:

- Be it known that I, FRrrz HARTNER, a sub'ect of the German Empire, and resident of omburg-vor-der-Hiihe, Germany, have invented certain new and useful Improvements in Mortar-Forming Materials; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

In the gypsum delposlits thelxl'e occui's in reat uantities IIDIC rite t at hit ierto aould niit be worked down Tor mortar making purposes. Anhydrite, that is the anhydrous modification of gypsum, without additions, does not give, even when most finely ground, a satisfactorily setting and hardening material. If fine powder of anhydrite is mixed with water, only after 30 hours a slight setting takes place, which however is essentially due to a drying process. Even the hardening being obtained by beating or stamping the water mixed anhydrite powder and molding it, is so small, that such use of anhydrite as a mortar forming material for technical building purposes is impossible.

There have already been made several experiments, it is true, to give the anhydrite by admixtures the property Ofhardening, but however without any practlcal success. I have made the surprising observation, that finely ground anhydrous gypsum is changed into a good mortar forming material by the admixture of some alkaline substances. If the mineral anhydrite is ground together with substances reacting alkaline, of which quite small quantities are suificient, the dead product changes into a plaster that sets and hardens well in few hours.

The object of the invention is therefore to change this anhydrous gypsum into a mortar forming material by grinding it together with alkaline substances. For thls purpose the alkali-oxide or hydroxids and especially th'oii sioi' li ydrox mthe alkaline earths come into consideration. First 5 of allthere must be mentioned calcium and .11 EYE vdroxid for instance .and calcium hZCIl'OXlCI u d Specification of Letters Patent.

Patented Mar. 15, 1921.

already caused the setting time of the powder of anhydrite to be reduced to four or at the most seven hours and the resulting mortar forming material to show already after 24 hours 7 to 8 kg/qcm. tensile strength, after 3 days 12 kg/qcm. after 7 days already more than 20 kg/qcm. and after 28 days almost 30 kg/qcm. These values refer to test pieces made by being cast into a mold. When manufactured by being pressed into a mold, even a mixture with 3 parts of sand showed after 7 days already a compremrength of 200 kg/qcm.

The quantity of the admixture of hydrate of lime may also be increased to or more. But the results of strength then do not change essentially. It is surprising that the small admixture of the substance that may be obtained so easily, produces a highly iinportant plaster from the useless anhy rite.

Instead of caustic lime pr hydratepilime materials containingthese substances-may be used, as Portland cement sla cements manufactured with I1me or P ortIand cement,

dead burnt lime and even waste building materials or waste building stones containing 0 lime. Finally may be mentioned lasterin and mortar dust. waste concrete an was e san e IlC s provlce t at ey stilIcontam Tree uvdrate of lime. These waste masla ed ieces which must be picked t Hem the slaked lime and thrown on the dump, if the lime plant in question did not possess effective grinding apparatus. This useless waste material from the lime-kiln is an excellent producer of the hardening capacity of the anhydrite. As it delivers caustic lime apparently only gradually, it proved to be an especially enduring admixture and it prevents degeneration upon storage.

The new mortar formin material is manufactured in a most simp e way by grinding together the anhydrite with the inciting substance. It is suitable to employ the degrees of fineness that are now used in the 105 ortland cement industry. But it is also txamaa suitable if ground anhydrite is mixed very carefully with the pulverized activating substance.

Just as with the proper gypsum it is also possible to influence the setting of this i: drite mortapigrmgg. by certain I ixtures.

Ihe manufacturing of a mortar with th1s new mortar formin material is done after adding or not adding lean or filling materials, just as with the gypsum.

c aim:

1. A mortar forming material comprising gypsum anhydrite and an alkaline substance.

2. A mortar forming material comprising gypsum anhydrite and a hydroxid having an alkaline reaction.

8. A mortar forming material comprising gypsum anhydrite and the hydroxid of a metal of the alkaline earths.

4. A mortar forming material comprising gypsum anhydrite and a substance capable of forming a h te of a metal of the alkaline earths upon the a 1 1on 0 wa r. v

5. mor ar a In using gypsum anhydrite and materials containing a substance having setting properties and containing a hydrate forming substance of alkaline properties.

6. A mortar forming material comprising gypsum anhydrite and Portland cement.

7 A mortar forming material comprising gypsum anhydrite ground with a small per centage of a substance having setting properties and an alkaline reaction.

8. A mortar forming material comprising gypsum anhydrite ground with a material containing lime, the percentage of lime being not over five per cent.

9. A mortar forming material comprising gypsum anhydrite ground with waste building material containing lime.

10. A mortar forming material comprising gypsum anhydrite and Portlant cement to an amount suflicient to carry lime to about five per cent. of the anhydrite.

In testimony that I claim the foregoing as my invention, I have signed my name in presence of two subscribing witnesses.

FRITZ HARTNER.

Witnesses:

ANNA SoHr'issLER, FRANZISKA GUTMANN.

SM. W 4727 mm 

